1. Field of Application
This invention relates to crusher jaws and more particularly to the swing jaw of a jaw type crusher.
2. Description of Prior Art
After rock, ore, and similar materials have been mined the pieces thereof are usually of mixed sizes, some of which might be extremely large. As such these materials are usually processed through suitable crushing equipment to reduce their size to one which can be more conveniently transported and/or to a size which is best suited for further processing toward the intended end use. One well known type of crusher is a jaw type crusher. In this equipment the material to be crushed is desposited between a pair of jaw members; one of which moves towards and away from the other. The jaws are mounted so that the spacing between them is greater at the material entrance and narrows towards the opening where the crushed material exits the crusher. Thus the movement of the movable jaw acts upon material lodged between the jaws to break up the material and reduce its size. As the size is thus reduced the material drops further down into the narrowing space between the jaws, until it exits the crusher at the intended size.
Commercially available jaw type crushers such as those shown in U.S. Pat. Nos. 1,608,561 and 3,804,345 cast the movable or swing jaw from suitable materials. However, casting requires a considerable investment in plant and labor if the crusher manufacturer desires to control his own supply of crusher jaws. If his output is too small to fully utilize the casting plant the operation becomes quite inefficient and costly. Quality control also presents considerable problems.
The cost of plant and labor (and hopefully of the jaws) may be reduced by relying upon vendors who operate casting plants to supply the swing jaw. Here again, quality control becomes a problem. In addition, depending upon the demands of the marketplace, obtaining castings, with reasonable lead times, has sometimes presented considerable problems. Also shipping of such casting adds to the cost thereof and at times presents serious complications especially for the larger swing jaws.
Some attempts have been made to alleviate these problems by fabricating the part of the swing jaw below the barrel which houses the bearings and shaft. In such equipment, however, the barrel with attendant support structures are still cast and the welding thereof to the remainder of the swing jaw body is accomplished along a plane through the assembly.
Most swing jaws have mounted proximate their lower extremities a toggle seat for co-operation with a toggle mechanism utilized to adjust the position of the lower end of the swing jaw with respect to the lower end of its opposing jaw. This controls the size of the spacing between the jaws, the exit opening and the material being crushed. Generally as shown in equipment such as that shown in the previously mentioned U.S. Pat. Nos. 1,608,561 and 3,804,345 a space must be machined into the casting to accept the toggle seat. Alternatively, as shown in U.S. Pat. No. 2,453,596, a rectangular bar is secured to the casting to receive the seat. There is extreme loading at the toggle seat area; and the stresses so created tend to concentrate and induce failure at the sharp corners of such prior art constructions.